The present invention relates to a nozzle assembly for an exhaust duct of a turbojet engine, more particularly such a nozzle assembly that is capable of diverting or vectoring the thrust from the turbojet engine.
It is known in the art to provide turbojet engines with exhaust nozzles having variable cross-sections in order to optimize the exhaust gas flow and pressure throughout the operational range of the aircraft. It is further known to provide such nozzles with a steering or vectoring capability in order to increase the maneuverability of the aircraft.
U.S. Pat. No. 4,778,109 to Jordain et al. discloses a two-dimensional exhaust nozzle arrangement having a converging-diverging configuration of variable cross-section in which the nozzle flaps also may deflect the exhaust gas stream at an angle to the longitudinal axis of the engine.
It is further known to provide generally annular exhaust nozzles with a moveable nozzle portion in order to deflect or vector the exhaust gases at an angle to the longitudinal axis of the engine. Such devices are shown in U.S. Pat. Nos. 4,363,445 to Bouiller et al. and 4,508,270 to Joubert.
While such known systems have proven reasonably successful, they are also complex, which results in the undesired increase in weight and bulk of the engine and, consequently, the aircraft. The increase in complexity is caused by the requirement of the prior art systems to not only pivot the annular array of flaps to vary the cross-section of the nozzle, but to also pivot the entire nozzle assembly to vector the exhaust thrust.